It ought not to be the W & R coin as that was ex Capt. V Hewitt, collection bought by Spink in 1967 and it was sold through Spink in 1994, not 1974 and also in London, not LA - all assuming the poster has the details right, of course. We haven't actually seen the obverse yet to confirm it has the adopted design as opposed to one of the other two. However, assuming it is the adopted obverse...
It is believed the 1994 sale coin was one of 2 known.
The provenances of two known examples are as follows:
The first -
A E Copp, portion of collection sold to R J Hopkins from 1887
R J Hopkins, Sotheby 15 Feb 1892, lot 116. Bt by Spink for £1/6/-
J G Murdoch, Sotheby 18 March 1904, lot 525. Weight 350 grains (22.665g). Bt by Spink £10/-/-
Baron P de Ferrari la Renotiere ('Nobleman'), Sotheby 29 March 1922, lot 331. Probably bt by Spink who were acting for Brand in this sale -
V M Brand (d.1926), collection split between brothers and dispersed from 1930s onwards.
Glendining 13 April 1972, lot 403. Graded strictly very fine. It was badly hairlined by this point based on the image and sold for £1150. I don't know who it sold to.
The second -
R Sainthill, Sotheby 27 April 1870, lot 352
S Addington, most of the collection purchased by Montagu in 1883
H Montagu, later milled coins purchased by Spink in 1890 and dispersed. This was coin no. 1595 in the catalogue.
As the weight is not that of the Murdoch coin, it is possible the 1994 coin was ex Montagu, but without documented records cannot be proven. Thankfully Montagu only had one example of an adopted design gold florin as there was no example in his duplicates sale in 1888.
If only two exist, that leaves the new arrival as the impaired ex-Murdoch piece, the weights in the Murdoch and 1972 catalogues being identical.